1. Field of the Invention.
This invention relates to a garment which prevents the loss of heat experienced with using mummy-style sleeping bags in very cold weather. More particularly, it relates to a sleeping garment which allows free movement in a sleeping bag while preventing the usual continual loss of heat through the breathing opening.
2. Prior Art
Most of the art in this area relates to attempts to design hoods which allow the wearer to stay warm while moving about in very cold weather. Attempts as early as 1904 included head, face and neck mufflers made of knitted wool and fitted closely to the head shape, as in U.S. Pat. No. 768,626 issued Aug. 30, 1904 and U.S. Pat. No. 787,945 issued on Apr. 25, 1905 both issued to Bernard Rautenberg. Other hoods which are adapted to be worn with other garments are disclosed in U.S. Pat. No. 2,839,757 issued Jun. 24, 1958 to S. V. Gianola, U.S. Pat. No. 2,870,452 issued Jan. 27, 1959 to J. De Grazia, and U.S. Pat. No. 4,768,235 issued Sep. 6, 1988 to M. Webster. These patents all focus on keeping the wearer warm while providing unobstructed vision. Design patent No. Des. 304,257 issued Oct. 31, 1989 to Dorning also shows a detachable hood and dickey combination which would enable the wearer to move about in cold weather.
The instant invention relates specifically to the equipment necessary for cold weather camping, necessitating sleeping at very low temperatures. At present, the best attempt to provide warmth to cold weather campers is a mummy-style sleeping bag which is a single piece sleeping unit with a drawstring in the face area which forms a breathing hole. This design, however, has two significant problems. First, if the sleeping person moves, the breathing hole is no longer centered over the nose and mouth. This causes condensation from the breath to settle in the hood of the bag thereby reducing its insulating value. Second, as the sleeping person moves in the bag, warm air gets pushed out through the breathing hole and cold air gets drawn in. This results in the continual loss of heat throughout the night. Unsuccessful attempts to solve this problem include the use of a special baffle around the neck. The most recent attempt to solve this problem is cold weather sleeping bags with a "draft collar" or "shoulder gasket" and a hood-shaped curve at the entrance to the bag. Normally the bag will be zipped first, then the hood drawstring will be tightened as much as one wants and finally the drawstring on the collar will be tightened. When the user gets to this last step there is not sufficient room for maneuvering the arms up around the shoulders making it difficult to adequately close the drawstring. Also, it is often difficult to find the drawstring due to this limited arm movement. In the alternative, the user could adjust the draft collar then zip up the bag last. However, this would still require one to snug-up the hood first, which would made it difficult to close the last few inches of the zipper.
For example, the most advance state of the art before the invention of the subject matter of this application involved an awkward procedure for securing a mummy-style sleeping bag. The advanced cold weather mummy-style sleeping bags have baffles or "gaskets" sewn into the inside of the bag in the shoulder area. Generally, one would get into the sleeping bag and put the baffles or gaskets in place over the shoulders. Then, with little room to maneuver one would zip the zipper up the side to the neck. Last, while so secured, one would have to reach the drawstring of the mummy-style hood (which is continuous with the entire bottom of the sleeping bag). With limited arm movement, this would require one to wriggle one's fingers through the neck hole formed by the shoulder gasket and pull down on the drawstring. Also, since the bags are standard size, the gasket must be located in the shoulder area of the average sleeping bag user. Accordingly, the tall or short user may find the location of the gasket unsatisfactory.